Decision-making Process of Mathematics Teacher in Responding to Student's Mistake

Students lack deep understanding and their learning needs, make it difficult for teachers to respond effectively to student errors. The case study investigated the decision-making process of teachers who respond to the student’s mistakes with solutions to quadratic function problems. This type of research is qualitative research with a descriptive approach. The results are revealed based on the decision-making stages: (1) generating ideas, the subject designed strategies using the GeoGebra application, and developing problems to train students’ HOTS skills. (2) Clarifying ideas, the subject considered students’ ability to understand the problem more easily if it is presented in visual form. (3) Assessing the fairness of ideas, the subject believed that when students were trained from carefully correcting their work to carefully proofreading their work, they learned from their mistakes and prevented them from repeating it. In conclusion, teacher can make good decisions by constructing and assessing ideas so that students can understand their mistakes. Keywords: decision making, mathematics teacher, quadratic function